(CNN) — Just north of Juchitan, in the city of Asuncion Ixtaltepec, neighbors gathered around the home of Eduardo Peralta, a father who they say died protecting his son during the magnitude 8.1 earthquake that shook Mexico Thursday.

Peralta's nephew told CNN en Español he found Peralta embracing his son inside their collapsed home. The father was dead, but the son survived and is being treated at a hospital, family members said.

Ninety people are now confirmed dead in the quake that struck off Mexico's southern coast. It was the most powerful to hit the country in a century and was felt as far as Mexico City and Guatemala City by an estimated 50 million people.

Many were asleep when the quake struck. The USGS reported multiple aftershocks, including at least six with tremors measuring above 5.0 in magnitude.

The majority of the deaths were in Oaxaca state, where homes and buildings collapsed. Oaxaca's governor said Saturday that 71 people had died in his state, Oaxaca's Civil Protection agency said via Twitter.

Relief and rescue efforts continued throughout the weekend.

In the city of Juchitan, rescuers used floodlights to illuminate a giant pile of debris.

"Can anyone hear me?" they shouted as they searched for survivors among the debris, using dogs to help in the search.

In other parts of Juchitan, operators used heavy machinery to clear roads. Soldiers tapped to help with relief efforts worked with shovels to move smaller debris out of the way.

Mexico's interior ministry has also reported 15 deaths in the state of Chiapas and four in the state of Tabasco.

Chiapas and Oaxaca, home to about 9 million people, are two of the most impoverished areas in Mexico.

The quake's epicenter was in the Pacific Ocean, some 600 miles (1,000 kilometers) southeast of Mexico's capital and 74 miles (120 kilometers) off the coast.

A tsunami was confirmed in Mexico, with one wave coming in at 5.8 feet (1.75 meter), according to the Pacific Tsunami Warning Center. Tsunami warnings were issued as far away as New Zealand and Vanuatu.

President Enrique Peña Nieto said Mexico's army, marines and federal police had been mobilized to respond.

The quake struck as the effects of Hurricane Katia were starting to be felt in eastern Mexico.

Eduardo Mendoza, general manager of Direct Relief Mexico, told CNN on Friday that the storm could complicate relief efforts and contribute to water-borne illnesses. Large trucks were having a difficult time reaching affected areas, he said, so individuals were bringing in supplies in their personal cars.

Mendoza said Direct Relief coordinates the delivery of supplies from companies in Mexico and the United States.

"What they really need right now are basic medical supplies for wound care and other trauma care," he said.

Also needing help are people who fled their residences and left their medications behind.

Mendoza said he felt the earthquake in his Mexico City residence.

"I could see my wall moving half a foot," he said. He ran outside but the building kept shaking 30 or 40 more seconds, he said.